Use GetValue and SetValue to get and save value to Registry : Registry : Development Class C# Source Code

    




using System;
using Microsoft.Win32;
class MainClass {
    public static void Main(String[] args) {
        string lastUser;
        string lastRun;
        int runCount;

        lastUser = (string)Registry.GetValue(@"HKEY_CURRENT_USER\Software\A\C#","", "Nobody");

        if (lastUser == null) {
            lastUser = "Nobody";
            lastRun = "Never";
            runCount = 0;
        } else {
            lastRun = (string)Registry.GetValue(@"HKEY_CURRENT_USER\Software\A\C#","LastRun", "Never");            runCount = (Int32)Registry.GetValue(
                @"HKEY_CURRENT_USER\Software\A\C#","RunCount", 0);
        }
        Console.WriteLine("Last user name: " + lastUser);
        Console.WriteLine("Last run date/time: " + lastRun);
        Console.WriteLine("Previous executions: " + runCount);

        Registry.SetValue(@"HKEY_CURRENT_USER\Software\A\C#","", Environment.UserName, RegistryValueKind.String);
        Registry.SetValue(@"HKEY_CURRENT_USER\Software\A\C#","LastRun", DateTime.Now.ToString(), RegistryValueKind.String);
        Registry.SetValue(@"HKEY_CURRENT_USER\Software\A\C#","RunCount", ++runCount, RegistryValueKind.DWord);
    }
}